Gravity in Brewing

Beer Glossary – Gravity: The Tipsy Scales of Brew Buoyancy!

Reading Time: around 5 min

When you grab a cold one from the fridge, you’re probably not pondering the physics of your beer. But get this: gravity in brewing is a big deal. It’s not just about keeping the beer in the glass and not on your couch.

It’s the secret sauce that tells brewers how potent your brew is going to be. Think of gravity as the X-ray specs of the beer world, letting brewers see right through the liquid to its boozy soul.

Now you might be wondering how someone measures this mystical ‘beer gravity.’ 

Well, imagine a tiny beer-loving buoy floating in your pint.

Measuring the density of the liquid like a mini submarine. That’s your trusty hydrometer. When brewers talk about “original gravity” (OG), they’re giving you the gossip on how much sugar was in the wort before fermentation waved its magic wand. 

After the yeast has its feast, “final gravity” (FG) spills the beans on the remaining sugars. The difference between them? That’s the magic number telling you how strong your beer will be. The more sugars eaten, the boozier the beer.

It’s like a caterpillar turning into a butterfly, but way tastier.

Achieving the desired gravity is a balancing act. 

Too much sugar at the start and you might end up with a beer that could double as a syrup. Too little, and your beer could be mistaken for hop-flavored water. The gravity tells you if you’ve hit the bullseye or if you’re shooting darts with noodles. 

It’s pivotal for brewing a beer that’ll make your taste buds throw a party without turning your head into a balloon animal after just one pint.

Key Takeaways

  • Gravity measures the beer’s potential strength by checking sugar content.
  • A hydrometer assesses OG and FG to reveal alcohol levels after fermentation.
  • Hitting the right gravity ensures a balanced and enjoyable beer.


Basics of Beer Gravity

Ready to dip your toe into the heady waters of beer gravity? 

It’s the secret sauce that turns sweet wort into your favorite brewski.

Gravity: The Force Awakens in Brewing

Think of gravity like the Yoda of brewing. It’s a sage indicator of potential alcohol content that brewers rely on. It’s not rocket science, but it’s science nonetheless. Before yeast works its magic, gravity gives us a sneak peek of the punch our future beer will pack.

Original Gravity (OG): The Starting Block

Original Gravity, or OG as the cool kids say, is like your beer’s birth certificate. Measured with a trusty hydrometer, OG tells you how much sugar is packed into your wort before fermentation starts. More sugar means more food for yeast.

Which means more alcohol for your pint. 

It’s all about that sweet potential.

  • Hydrometer: It’s your Sherlock Holmes, deciphering the density of your brew.


Final Gravity (FG): The Endgame

Once the yeast has had its feast, FG rolls in like the closing credits of a movie. It reveals how much sugar the yeast left behind, and that tells you the alcohol content. 

You want your FG low; this isn’t a sugar rush we’re after. If your OG was “The Empire Strikes Back,” think of your FG as “Return of the Jedi”. The resolution of an epic saga.

  • Ideal FG Range: Imagine a dartboard, where bulls-eye is your perfect beer profile. That’s your target FG.


From Science to Pint: Measuring and Impact

Brewing is part art, part science, and a whole lot of gravity talk. 

Wrap your head around these concepts.

And you’ll predict the future of your beer like a boozy oracle.

Reading the Liquid Crystal Ball: Hydrometers and How They Predict Your Beer’s Future

Imagine a tiny submarine (known as a hydrometer) that can foresee if your next brew is going to be a lightweight or the heavyweight champion of beers. When you dunk a hydrometer into your mash, it floats to a level that tells you the gravity. 

Gravity is basically how much sugar is packed in there, waiting to turn into alcohol. Higher gravity? Brace for a stronger beer. Lower gravity? It’s relaxation in a bottle.

  • Initial Gravity (IG): When you first measure your unfermented mash.

  • Final Gravity (FG): The revelation once fermentation wraps up.

The difference between those two tells you how much sugar your yeast converted into alcohol. It’s like watching your beer go to the gym; the bigger the change, the beefier the beer.

Alcohol By Volume (ABV): How Strong Is Your Brew?

ABV is the muscle of your beer. 

The percent of liquid that’s pure, unadulterated alcohol. It’s a straightforward equation: the more sugar your yeast devours, the higher the ABV. Expecting a light, breezy ale? Aim for low gravity. 

Dreaming of making your taste buds tango with a potent porter? 

Crank that gravity up!

  • Low ABV (<5%): It’s a session beer. Go ahead, have another.

  • High ABV (>8%): Treat it like an angry bear. Approach with respect.

Carbonation and Body: Putting the Fizz in Physics

Alright, let’s talk bubbles! Your brew’s carbonation makes it dance on your tongue, and it’s all about the CO2. Yeast is your tiny bubble factory, turning sugar into carbon dioxide and giving your beer that snappy personality. 

And the body? It’s beer’s handshake, telling you if it’s going to be a firm, full-bodied sip or a light, ticklish encounter. Get your mash’s gravity in the sweet spot, and you’ll sculpt the perfect body. 

It’s like yeast pumping iron to build your beer’s physique.

  • Low Carbonation: Gentle like a butterfly’s landing.

  • High Carbonation: Pop, lock, and drop it – it’s a party in your glass!

Picture of Damian


A lifelong learner, hop enthusiast and a lover of the state of extreme exhaustion.

Finance Analyst in the Investment Bank and co-founder of